Recently, AM (Additive Manufacturing) techniques to fabricate a shaped product that matches a shaping object by sequentially stacking shaping materials corresponding to cross-sections generated by sectioning a three-dimensional shaping object by parallel planes, are receiving attention.
Various methods are known as AM techniques, but in many methods the shaping object or parts must be fixed on a reference stage by a support during fabrication. This support is used for preventing deformation of the shaping object during fabrication.
This support must maintain sufficient structural strength to withstand gravity and tensile strength, which are applied to the support during fabrication of parts. In particular, the lower side of the portion where the shaping object protrudes (overhanging portion) is a typical region that requires the support to prevent deformation caused by gravity. Hereafter, the portion constituting the shaping object, in the shaped product fabricated by an AM technique, is called a “structure” to distinguish it from the support.
When the fabrication of the shaped product completes, the support must be manually removed from the structure or must be dissolved by a solvent. This removal step is extremely time consuming, and requires considerable care so that the surface of the structure is not damaged during removal.
Further, since the removed support becomes waste, conserving time, energy and materials to fabricate the support is demanded.
PTL 1 discloses various methods to decrease material consumption while maintaining the structural strength of the support.
PTL 2 discloses a method of calculating a support required region, calculating joint points of the structure and the support, and reducing unnecessary support by using a ranking method, which is determined from the joint points by special calculation.
PTL 3 discloses a method of calculating the thickness of the wall of the support using the weight distribution of the shaping object, where the thickness of the wall of the support, corresponding to a portion of which weight per unit volume is large, is made thicker than other portions.